Introducing the new Kid on the Block: PRP – or Platelet Rich Plasma injections

One of the hot topics in Sports Med recently is the Platelet Rich Plasma injection, but what is it, what does it involve and is it any good for you? This blog post explores the first two questions but the third question we’ll answer in the next one.

So what is a platelet?

From the name we can confidently say that this therapy involves platelets. Platelets are little broken up red blood cell fragments, a cell nucleus without a cell body, just the inside of a cell. Being just a nucleus they are a good bit smaller than a regular white or red blood cell. Because they are a different shape and size they can therefore do something different to other blood cells and the thing they are really good at doing is clumping up. The thing they clump up best on is a broken blood vessel, which makes them very good at wound healing. If one of your blood vessels is broken your platelets will stick to the edge of it.

The other thing your platelets are good at sticking too is other platelets. When a blood vessel is broken or a tissue is torn your platelets stick to it and then they stick to any other platelet that flows past. In this way your body can quickly build up a cover over its abrasions, breaks and bleeds with minimum fuss. This is the first step of wound healing and it seems to act as a prompt or a signal to our other healing mechanisms to get started.

But what makes it rich?

Well with this technique the treating practitioner gets a machine with a needle on the end and takes between 100 and 180cc’s of blood out of the patient, give or take. It’s not enough to really feel light headed or low on energy or anything like that. The machine spins the blood in a centrifuge; this has the effect of separating it into its different constituents, red blood cells, white blood cells and the plasma. In the plasma live the platelets, the platelets are extracted from the rest of the blood and then large concentration of them are put into a small volume of plasma, enriching it. This Platelet Rich Plasma is then injected back into the site of an injury.

What do we do with Platelet Rich Plasma?

It is used for a lot of the trickier, hard to treat injuries, like muscle tears. Examples include muscle tears like hamstring strain and tendon degenerative injuries, like achilles tendinopathy, or lateral epicondylitis (tennis elbow). These names are argued over a bit in medical sciences, some going in and out of fashion but broadly speaking if you have a tendonitis, tendinosis, tendinosus, tendinopathy, paratenonitis, paratendinopathy or degenerative tendon tear then our next article, where we discuss how well this works, might be relevant to you.